O-alkyl-o-phenyl-s-alkoxyethyl-phosphoro-thiolates

ABSTRACT

O-alkyl-O-phenyl-S-alkoxyethyl-phosphorothiolates of the general formula IN WHICH R1 and R2, which may be the same or different, denote alkyl radicals of one to four carbon atoms, EACH X independently denotes a halogen atom, and N IS 0, 1, 2 OR 3, WHICH POSSESS INSECTICIDAL, FUNGICIDAL AND NEMATOCIDAL PROPERTIES.

United States Patent Kishino et a]. 1 Sept. 5, 1972 [54] o-ALKYL-o-PHENYL-s- [56] References Cited ALKOXYETHYL-PHOSPHORO- FOREIGN PATENTS OR APPLICATIONS THIOLATES 624,475 9/1961 Italy ..260/950 x Inventors: Shigeo Kishino, Tokyo; Kozo Shiokawa; Akio Kudamatsu, both of Kanagawa-ken; Yasuo Yamada,

Tokyo, all of Japan Assignee: Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany Filed: July 23, 1970 App]. No.: 57,793

Foreign Application Priority Data Primary Examiner-Joseph Rebold Assistant Examiner-Anton l-l. Sutto Attorney-Burgess, Dinklage & Sprung [57] ABSTRACT O-alkyl-O-phenyl-S-alkoxyethyl-phosphorothiolates of the general formula in which R and R which may be the same or different, denote alkyl radicals of one to four carbon atoms, each X independently denotes a halogen atom, and nisO, 1,2or3,

which possess insecticidal, fungicidal and nematocidal properties.

38 Claims, N0 Drawings O-ALKYL-O-PHENYL-S-ALKOXYETHYL- PHOSPHORO-THIOLATES The present invention relates to certain new thiophosphoric acid esters, to a process for their production and to their use as insecticides and fungicides.

The present invention provides thiophosphoric acid esters of the general formula:

It has been found that the organic thiophosphoric acid esters of the said general formula (I) possess insecticidal and fungicidal properties.

The phosphoric acid esters of the present invention possess an excellent insecticidal activity and they can be used to control a wide range of insect pests such as noxious sucking and biting insects and insect pests which are parasitic on plants. The esters of the invention can be effectively applied as insecticides against pests of rice, fruit trees and vegetables, including pests of the orders Coleoptera, Lepidoptera and Diptera; the esters may also be used against plant parasitic nematodes and soil nematodes.

Furthermore, the thiophosphoric acid esters of the invention possess excellent fungicidal activity as well as reproduction-inhibiting activity in respect of plant pathogenic fungi; therefore, they can be applied for the control of various kinds of plant pathogenic fungi. The esters can be effectively used as fungicides in cases of diseases caused by Archimycetes, Phycomycetes, Ascomycetes, Basidiomycetes and Fungi imperfecti. A remarkably good effect is obtained when the esters are used against plant pathogenic fungi or rice, fruit trees and vegetables.

Compounds of the formula (I) in which the phenyl ring carries a chlorine or bromine atom at each of the 2, 4, and 5 positions possess characteristic fungicidal activity.

As mentioned above, the compounds according to the present invention have broad and excellent biological activity as they show both insecticidal and fungicidal properties and, therefore, they are of great practical value. Moreover, these compounds do not contain heavy metals as organic mercury compounds do; as a result, it is unnecessary to worry about residual toxicity in crops. The compounds of the invention also have low toxicity; they do not show such acute toxicity as, for example, Parathion. These features of the esters of formula (I) provide a great advantage in the handling of the agricultural formulations thereof.

The present invention also provides a process for the production of the esters of formula (I) in which (a) an O,S-diester of a thiophosphoric acid halide of the formula mo 0 P-hal moomoms is reacted with a phenol or phenolate of the formula n MO- (III) is reacted with a l-halo-2-alkoxy ethane of the formula 1 l-Ial-Clh-CIL-OR v in which R, R X and n have the meanings given above,

M is a hydrogen atom, a metal equivalent or an ammonium radical, and

Hal is a halogen atom.

R and R are alkyl radicals of one to four carbon atoms, namely methyl, ethyl, nor iso-propyl, n-, iso-, secor tert-butyl radicals, preferably methyl, ethyl, nor iso-propyl, n-, isoor sec-butyl radicals. Each X is a halogen atom such as a chlorine, bromine, fluorine or iodine atom, preferably a chlorine or bromine atom. n is 0 or an integer of l to 5, preferably 1, 2 or 3. M is a hydrogen atom, an ammonium radical, a metal equivalent, especially an alkali metal atom such as a sodium, potassium or lithium atom; M is preferably a hydrogen, sodium or potassium atom, or an ammonium radical. Hal is a halogen atom such as a chlorine, bromine, fluorine or iodine atom, preferably a chlorine atom.

The process can be carried out by reacting the starting materials directly, but it can be also carried out by using an inert solvent or diluent. The reactants are conveniently used in equimolar amounts.

Suitable solvents and diluents include aliphatic or aromatic hydrocarbons (which may be halogenated), for example, benzine, methylene dichloride, chloroform, carbon tetrachloride, benzene, chlorobenzene, toluene and xylene; ethers, for example, diethylether, dibutylether, dioxane and tetrahydrofuran and aliphatic alcohols or ketones with low boiling points, for example, methanol, ethanol, isopropanol, acetone, methylethylketone, methylisopropylketone and methylisobutylketone. Lower aliphatic nitriles such as acetonitrile and propionitrile are also usable.

The reaction may be carried out in the presence of an acid-binding agent; this is especially advantageous when M is a hydrogen atom. For this purpose, there may be used alkali metal carbonates, bicarbonates and alcoholates, such as sodium hydrogen carbonate, potassium carbonate, sodium carbonate and potassium or sodium methylate or ethylate, and tertiary aliphatic, aromatic and heterocyclic amines, such as triethylamine, diethylaniline and pyridine.

The process variant (a) may be carried outwithin a fairly wide temperature range, generally from to 1 C, preferably from 10 to 80 C.

The starting material of the formula (11) may be prepared according to generally known methods, for example, by reacting an S-(2-alkoxy)ethy1dihalide phosphorothiolate with an alcohol or a metal alcoholate in an inert solvent or diluent. This reaction may be carried out in the presence of an acid-binding agent as occasion demands, for example, when an alcohol is employed as a reactant.

The process variant (b) can be carried out within a fairly wide temperature range; generally, the reaction is effected at from 0 to 100 C, preferably from 30 to 80 C.

The starting material of the formula (IV) may be prepared according to generally known methods. For

example, an O-alkyl-O-substituted-phenylthionophosphoryl chloride may be reacted with an alkali hydroxide. The resulting O-alkyl-O-substitutedphenylthio-phosphoric acid salt may be used after separation or it may be used in situ without separation, by reacting it with a l-halo-2-alkoxyethane to obtain the desired product of the general formula (1) The following Example illustrates the process for preparing compounds of the present invention.

EXAMPLE 1 O H O CHZOHQS 32.5 g of the potassium salt of O-ethyl O-(2,4- dichlorophenyl)thiophosphoric acid are dissolved in 70 ml of alcohol and 16 g of 2-ethoxyethylbromide are added to the solution. The mixture is stirred at 60-70 C for 3 hours. The resulting inorganic salt is filtered off. After distilling off the alcohol, the residue is dissolved in benzene. The benzene solution is washed with a 1 percent sodium carbonate solution and then with water, and is then dried over anhydrous sodium sulphate. After distilling off the benzene, the residue is distilled under reduced pressure and 21 g of O-ethyl O- (2,4-dichlophenyl) S-(2-ethoxy-ethyl)phosphorothiolate are obtained; b.p. l6ll70 C/0.2 mml-lg, n 1.5331. This compound is designated hereinafter by the number 22. The preparation of the potassium salt of O-ethyl- O-(2,4-dichlorophenyl)-thiophosphoric acid may be carried out as follows:

34 g of potassium hydroxide are dissolved in 200 ml of water and 200 ml of dioxane are added to the solution. While stirring the solution vigorously, 92 g of O- ethyl O-(2,4-dichloro-phenyl)thionophosphorylchloride are added dropwise at 3040 C. After the addition, thereaction temperature is raised gradually, and the stirring is continued at 60-70 C for 1 hour to complete the reaction. Then the dioxane and water are distilled off under reduced pressure. The residue is dis solved in acetone and the inorganic salt is filtered off. After distilling off the acetone and adding toluene and n-hexane to the residue and filtering off the precipitate, g of crude crystals of the potassium salt of OO-ethyl O-(2,4-dichlorophenyl)thiophosphoric acid are obtained.

Representative compounds which may be prepared by methods similar to the method stated above are shown in the following Table.

TABLE 1 1H1) X" Q 1() RQOCIIZCHZS/ (1) Boiling Refraction Point coefficient Compound R R X, (C/mmHg) (n 1 CH, c 11 11 0 2 0 1-1, C11 11 o 3 c 11, c,1-1, n 0 14o-144 0.2 1.5141 4 c 11, n-c,1-1, n 0 137-142/0.o5 1.5085 5 0,11, i-C l-l, n o 1s0 1s4/0.1 1.5069 6 C 11 5 n-C H n 0 l45-l50/0.05 1.5058 7 i-C 1-1 C 11 n 0 -150/008 1.5068 s c 11 c1-1 2 c1 9 C H n-C H, 2-C1 140144/0.07 1.5202 10 c 11, sc n, 20 11 C 11 C 11 2-C1 l39l43/0.15 1.5245 12 c 11, 0 1-1, Z-Br 13 CH C 11 4-C1 1.5414 14 C H CH 4-C1 15l156/0.13 1.5270 15 C 11,, C 11 4-C1 l40-l45/0.1 1.5 229 16 c, m n-C H 4-01 l45l50/0.l 1.5179 1 7 11, 10,11, 4-c1 18 C H n-C,l*1 4-C1 19 0,11, 0,11, 4-121 20 CH,, C 11,, 2,4'C1 1.5575 21 C H CH; 2,4-Cl, l45153/0.1 1.5390 22 C H C 11 2,4-C1 l6l-170/O.2 1.5331 23 CgH5 n-C H 2,4-C1 l50/0.08 1.5291 24 C H i-C -,H 2,4-Cl l60166/0.3 1.5275 25 C 11,, n-C H 2,4-C1 160-168/0.3 1.5248 26 i-C H C H 2,4-C1 160l62/0.2 1.5240 27 n-C H C 11 2,4-C1 28 n-C.H C 11 2,4-Cl 29 0 11, c 11, 2,5-c1 30 C H C 11,, 2,4-Br 31 C,H CH 2,4,5-C1 32 C H, C l-1 2,4,5-C1 155/O.15 1.5461 33 C 11,, i C H 2,4,5,-C1; 34 n-Cfl-l, C 11 2,4,5-C1 35 C 11 C l-1 2,4,6-C1 36 C 11, Cg"; 2,5-C1 4-31 When the compounds according to this invention are in insecticidal fungicidal compositions, they may be applied after dilution with water, using solvents or adjuvants as occasion demands, or they may be formulated into various types of formulations by mixing them with various kinds of inert gases, liquid or solid diluents and/or carriers and, as occasion demands, using adjuvants such as surface-active agents, emulsifying agents, dispersing agents, developers and adhesive agents according to the methods generally practised in the manufacture of agricultural compositions.

As gaseous diluents or carriers, freon or other propellant gases in normal condition for aerosol use, are employed.

The active compounds according to the present invention can be converted into the usual formulations, such as solutions, emulsions, suspensions, powders, pastes and granulates. These may be produced in known manner, for example by mixing the active compounds with extenders, that is, liquid or solid diluents or carriers, optionally with the use of surface-active agents, that is, emulsifying agents and/or dispersing agents. In the case of the use of water as an extender, organic solvents can, for example, also be used as auxiliary solvents.

As liquid diluents or carriers, there are preferably used aromatic hydrocarbons, such as aromatic naphthas, toluene, xylenes, dimethylnaphthalenes or benzene, chlorinated aromatic and aliphatic hydrocarbons, such as chlorobenzenes, carbon tetrachloride, methylene dichloride, and chloroethylene, paraffins, such as mineral oil fractions, cyclohexane, alcohols, such as methanol, ethanol, propanol or butanol, or strongly polar solvents, such as dimethyl formamide or dimethyl sulphoxide, as well as water.

As solid diluents or carriers, there are preferably used ground natural minerals, such as bentonite, atapulgite, kaolins, montmorillonite, clays, talc, diatomaceous earth, or chalk, or ground synthetic minerals, such as highly-dispersed silicic acid or silicates and alumina.

Preferred examples of emulsifying agents include non-ionic and anionic emulsifiers, such as polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol ethers, for example alkylarylpolyglycol ethers, alkyl sulphonates and aryl sulphonates; and preferred examples of dispersing agents include lignin, sulphite waste liquors and methyl cellulose.

As occasion demands, other agricultural chemicals, such as insecticides, nematocides, fungicides (including antibiotics), herbicides, plant-growth regulators, or fertilizers can be present.

Insecticidal and fungicidal compositions according to the present invention generally contain 0.1 95 percent, preferably 0.5 90 percent by weight of the active compound. The amount of the active compound or compounds contained in the compositions can be varied according to the types of formulation, methods of application, and the purpose, time and place of application as well as the conditions of outbreak of diseases.

Active compounds according to the present invention can be used as they are, or by formulating them into all types of ready-to-use formulations employed in the art, such as liquids, emulsions, emulsifiable concentrates, wettable powders, soluble powders, oil aerosols, pastes, fumigants, dust, granules, pellets, and tablets.

Application of these compositions is carried out by, for example, mixing, watering, spraying, atomizing, misting, dusting, scattering, fumigating, drenching, dressing the insect pests and/or fungi and/or their habitat through direct application or by using any suitable apparatus. The active compounds according to the present invention can also be used in accordance with the well-known ultra-low-volume (ULV) process. According to this method, the preparation may contain up to 95 percent by weight of active compound or even the active compound alone.

The amount of active compound in the ready-to-use preparation can be varied within a fairly wide range. Generally, the preparation contain 0.005 10 percent, preferably 0.01 5.0 percent, by weight of the active compound.

The quantity of active compound applied to an area of agriculture is generally between from 0.15 10 kg per hectare, preferably from 0.4 13 6 kg per hectare. However, in special cases, it is possible to increase or reduce the amount and actually it is sometimes necessary.

The present invention provides an insecticidal and fungicidal composition containing as active ingredient an ester of the present invention in admixture with a diluent or carrier. When a liquid diluent is used, it preferably contains a surface-active agent.

The present invention also provides a method of combating insects and fungi which comprises applying to the insects or fungi, or to an insect or fungus habitat, an ester of the present invention alone or in the form of a composition containing as active ingredient as ester of the present invention in admixture with a diluent or carrier.

The present invention further provides a method of providing a harvested crop which comprises applying an ester of the invention to the area of cultivation of the crop whereby the latter is protected from damage by insects or fungi, and harvesting the crop.

The present invention also provides crops protected from damage by insects or fungi by being grown in areas in which immediately prior to and/or during the time of the growing an ester of the present invention was applied alone or in admixture with a diluent or carrier.

The compositions of the invention are illustrated in and by the following Examples.

EXAMPLE (I) 15 parts of Compound No. 11 as identified in Table l, parts of a mixture of diatomaceous earth and kaolin and 5 parts of an emulsifier, Runnox (trade name of a product of Toho Kagaku Kogyo K.K.), are mixed and crushed to produce a wettable powder. It is used after dilution with water.

EXAMPLE (ll) 30 parts of Compound No. 22, 30 parts of xylene, 30 parts of Kawakasol (trade name of a product of Kawasaki Kasei Kogyo K.K.) and 10 parts of an emulsifier, Sorpol (trade name of the product of Toho Kagaku Kogyo K.K.), are mixed and stirred to formulate an emulsifiable concentrate. It is used after dilution with water.

EXAMPLE (III) To a mixture consisting of 10 parts of Compound No. 32, 10 parts of bentonite, 78 parts of zeeklite and 2 parts of lignin sulphate, 25 parts of water are added and the mixture is firmly kneaded. It is cut into granules of 20-4O mesh by a push-out type mulmerizer. The granules are then dried at 4050 C to provide a granular formulation.

EXAMPLE 1v 2 parts of Compound No. 3 and 98 parts of a mixture of talc and clay are mixed and crushed, and used as a dust formulation.

The compounds according to the present invention are characterized by substantially improved efficacy and extremely low toxicity to warm-blooded animals compared with the known compounds with similar structure and mode of action disclosed in the literature. Therefore, they are of great practical value. The effectiveness of the present compounds is illustrated in the following Examples, in which compounds are identified by the numbers given in Example 1.

Example A Test against tobacco cutworm larvae Test procedure:

Leaves of sweet potato were dipped in dilute aqueous solutions of a compound of the present invention of the prescribed concentrations and dried. They were placed in Petri dishes of 9 cm diameter.

10 tobacco cutworm larvae (Prodenia litura) of 3 instar were put into each of the Petri dishes thus prepared. The dishes were placed in an incubator kept at 28 C.

24 hours later, the number of dead insects were counted and the mortality was calculated.

The results are shown in the Table 2.

TABLE 2 Results of test against tobacco cutworm larvae Active Mortality (in percent) at the concentration of Compound 1,000 ppm 300 ppm lOO ppm l 100 80 2 100 80 20 2 100 I 70 4 100 W0 30 5 100 100 80 6 100 80 30 7 100 50 8 100 100 90 9 100 90 30 10 100 70 l0 1 l 100 100 90 12 100 100 90 13 100 50 I4 100 100 75 l5 100 100 100 I6 100 100 80 17 100 100 60 18 100 lOO 9O 19 100 I00 100 20 100 60 21 I00 100 I00 22 100 100 100 23 I00 I00 50 24 100 100 80 25 I00 100 50 26 I00 50 l0 27 100 90 40 28 I00 80 29 100 100 100 30 I00 100 60 3i 100 100 90 32 l00 100 100 33 I00 100 50 34 I00 60 35 100 I00 90 36 I00 I00 100 Dipterex I00 25 0 (Comparison) Lebaycid 3O 0 0 (Comparison) Notes: I Dipterex: dimethyl-Z,2,2-trichlorol -hydroxyethyl phosphonate.

2) Lebaycid: dimethyl-4-(methylthio)-3-methylphenyl thiophosphate.

EXAMPLE B Test against Fall webworms Test Procedure:

Leaves of mulberry were dipped in dilute aqueous solutions of a compound of the present invention of the prescribed concentrations and dried. They were placed in Petri dishes of 9 cm diameter.

10 Fall webworms larvae (Hyphantria cunea) of 4 instar were placed in each of the dishes thus prepared. The dishes were placed in an incubator kept at 25 C.

24 hours later, the number of dead insects was counted and the mortality was calculated.

The results are shown in the Table 3.

TABLE 3 Results of test against Fall webworms Active Mortality (in percent) at the concentrations of Compound 1,000 ppm 300 ppm 100 ppm 3 100 I00 80 5 I00 100 20 8 I00 I00 60 l 1 I00 100 100 l 2 I00 100 I00 13 I00 90 14 l 00 I00 40 l 5 I00 I00 2O )0 40 21 100 I00 22 100 I00 100 23 I00 100 I00 24 100 100 I00 25 I00 29 lOO 100 80 30 100 100 I00 32 l 00 I00 I00 35 100 I00 50 36 100 100 lOO Dipterex I00 I00 20 (Comparison) Lebaycid 0 0 (Comparison) EXAMPLE C Test against rice stem borer larvae Test procedure:

To paddy rice plants at the tillering stage, which were planted in pots of 12 cm diameter, egg masses of the rice stem borer (Chilo supperssalis) were attached.

7 days after the eggs had hatched, a dilute aqueous solution of a compound of the present invention prepared from an emulsifiable concentrate was sprayed in an amount of 40 ml per pot using a spray-gun.

The pots were left in a green-house. Three days after the treatment, the numbers of surviving and killed insects in the rice stalks were counted and mortality was calculated.

The results are shown in Table 4.

TABLE 4 Results of test against rice stem borer larvae Mortality (in percent) Test against adult house flies Test procedure:

1 ml of a dilute solution of a compound of the present invention of the prescribed concentration was applied to a filter paper placed in a Petri dish of 9 cm 20 diameter.

10 mature female house flies (Musca domestica) were put in each of several such Petri dishes and left in an incubator kept at 28 C.

24 hours later, the number of dead insects was 2 counted, and the mortality was calculated.

The results are shown in Table 5.

TABLE 5 30 Results of test against adult house flies Active Mortality (in percent) at the concentration of Compound I,000 ppm I ppm 3 100 100 5 100 90 35 6 100 80 s 100 90 10 100 100 11 100 100 12 100 100 13 100 100 14 100 90 40 15 100 100 16 100 100 19 100 100 20 100 100 21 100 100 22 100 100 23 100 100 45 24 100 100 25 100 100 29 100 100 30 100 100 32 100 100 35 100 100 36 100 100 Dipterex I00 I00 (Comparison Example E Test agalnst the German Cockroach (Blattella germamca) The test was carried out using the same procedure as 1n Example D.

The results are shown in Table 6.

TABLE 6 Results of test against German cockroach Active Mortality (in percent) at the concentration of Compound 1,000 ppm 100 ppm I2 I00 I00 I3 I00 I00 15 I00 I00 I9 I00 I00 22 I00 I00 24 I00 I00 29 I00 I00 32 I00 I00 What we claim is:

l. Thiophosphoric acid esters of the general formula IHOCIIQCIIQS in which R and R', which may be the .same or different, denote alkyl radicals of one to four carbon atoms, each X independently denotes a halogen atom, and

nisO, l,2,or3.

2. Esters according to claim 1 in which R and R 3. The ester according to claim 1 of the formula CllnU' 021150 CIIzCHzS 4. The ester according to claim 1 of the formula (2 I19 0 CIIgCIIrS 7. The ester according to claim 1 of the formula 8. The ester according to claim 1 of the formula each denote a methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl or sec-butyl radical, each X denotes a chlorine or bromine atom and n denotes I 2 or 3.

9. The ester according to claim 1 of the formula 10. The ester according to claim 1 of the formula CHaO CH'ICI'IQS 1 l. The ester according to claim 1 of the formula 12. The ester according to claim 1 of the formula Cl C2II5O\\[Ol /1 iO H enact-12s 13. The ester according to claim 1 of the formula 14. The ester according to claim 1 of the formula Br OQHSO O C2H OCHzCHzS 15. The ester according to claim 1 of the formula CHaO o 16. The ester according to claim 1 of the formula CzHsO 17. The ester according to claim 1 of the formula 18. The ester according to claim 1 of the formula 19. The ester according to claim 1 of the formula Call) U 20. The ester according to claim 1 of the formula 0mm o l n (nu,oou-,oms

21. The ester according to claim 1 of the formula 24. The ester according to claim 1 of the formula C2II5O 0111201123 25. The ester according to claim 1 ofthe formula \1O or n-CsH10CI'IzCIIzS 26. The ester according to claim 1 of the formula 27 The ester according to claim 1 of the formula 28. The ester according to claim 1 of the formula C2H5OCH2CH2S (26) 29. The ester according to claim 1 of the formula C2H5OCH2CH2S 30. The ester according to claim 1 of the formula C H O CHgCHzS (28) 31. The ester according to claim 1 of the formula 34. The ester according to claim 1 of the formula L -C (1 1150 CIIzCIIaS C1 35. The ester according to claim 1 of the formula 'CHOCH CH S l 37 2 2 G1 36. The ester according to claim 1 of the formula WM swoon-,02 s (I 37. The ester according to claim I of the formula 38. The ester according to claim 1 of the formula Cl CzHrO O C zHsOCHzC H: S 01 UNITED STA'IICS .lfso'll'lN'l. OFFICE CERTHFICA'IE!) OI CORRECTION Patent No. 3 689 i Dated September 5 1972 Inventor(s) Shigeo Kishino et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 4 line 6 Change "OO-ethyl-" to O-ethyl Col. 4, line 36 Comp. 16

n n Change C to C H Col. 4 line 55 Between "insecticidal" and "fungicidal" insert and Col. 6 line 9 Change "0.413 6 kg." to 0.4 6 kg.

Col. 14 line 12 Change "C H O" to C 11 Signed and sealed this 6th day of March 1973.

(SEAL) Attcst:

EDWARD M. FLE1'CHER,JR. ROBERT GOTTSCIIALK Attesting Officer Commissioner of Patents 

2. Esters according to claim 1 in which R1 and R2 each denote a methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl or sec-butyl radical, each X denotes a chlorine or bromine atom and n denotes 1, 2 or
 3. 3. The ester according to claim 1 of the formula
 4. The ester according to claim 1 of the formula
 5. The ester according to claim 1 of the formula
 6. The ester according to claim 1 of the formula
 7. The ester according to claim 1 of the formula
 8. The ester according to claim 1 of the formula
 9. The ester according to claim 1 of the formula
 10. The ester according to claim 1 of the formula
 11. The ester according to claim 1 of the formula
 12. The ester according to claim 1 of the formula
 13. The ester according to claim 1 of the formula
 14. The ester according to claim 1 of the formula
 15. The ester according to claim 1 of the formula
 16. The ester according to claim 1 of the formula
 17. The ester according to claim 1 of the formula
 18. The ester according to claim 1 of the formula
 19. The ester according to claim 1 of the formula
 20. The ester according to claim 1 of the formula
 21. The ester according to claim 1 of the formula
 22. The ester according to claim 1 of the formula
 23. The ester according to claim 1 of the formula
 24. The ester according to claim 1 of the formula
 25. The ester according to claim 1 of the formula
 26. The ester according to claim 1 of the formula
 27. The ester according to claim 1 of the formula
 28. The ester according to claim 1 of the formula
 29. The ester according to claim 1 of the formula
 30. The ester according to claim 1 of the formula
 31. The ester according to claim 1 of the formula
 32. The ester according to claim 1 of the formula
 33. The ester according to claim 1 of the formula
 34. The ester according to claim 1 of the formula
 35. The ester according to claim 1 of the formula
 36. The ester according to claim 1 of the formula
 37. The ester according to claim 1 of the formula
 38. The ester according to claim 1 of the formula 